When the terrifying pictures of September 11th appear on television, do you let your children watch?
What do you tell them about anthrax or the bombing of Afghanistan? This week Tony Blair said that he tried to explain to his children that there's a choice - either you sit back or try to stop the people responsible.
You may not take the same approach but when so many conversations are dominated by the news, children are inevitably affected by the cataclysmic images around them.
Martha is joined by Lynn Barnett, a Consultant Child Psychotherapist, who has studied the effects of war on children for 30 years, and Rachel Evans, Producer of Newsround on BBC TV.